Generalization error bounds for kernel matrix completion and extrapolation

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Prior information can be incorporated in matrix completion to improve estimation accuracy and extrapolate the missing entries. Reproducing kernel Hilbert spaces provide tools to leverage the said prior information, and derive more reliable algorithms. This paper analyzes the generalization error of such approaches, and presents numerical tests confirming the theoretical resultsThis work is supported by ERDF funds (TEC2013-41315-R and TEC2016-75067-C4-2), the Catalan Government (2017 SGR 578), and NSF grants(1500713, 1514056, 1711471 and 1509040).Peer ReviewedPostprint (published version

Acclimatised rumen culture for raw microalgae conversion into biogas: Linking microbial community structure and operational parameters in anaerobic membrane bioreactors (AnMBR)

[EN] Ruminal fluid was inoculated in an Anaerobic Membrane Reactor (AnMBR) to produce biogas from raw Scenedesmus. This work explores the microbial ecology of the system during stable operation at different solids retention times (SRT). The 16S rRNA amplicon analysis revealed that the acclimatised community was mainly composed of Anaerolineaceae, Spirochaetaceae, Lentimicrobiaceae and Cloacimonetes fermentative and hydrolytic members. During the highest biodegradability achieved in the AnMBR (62%) the dominant microorganisms were Fervidobacterium and Methanosaeta. Different microbial community clusters were observed at different SRT conditions. Interestingly, syntrophic bacteria Gelria and Smithella were enhanced after increasing 2-fold the organic loading rate, suggesting their importance in continuous systems producing biogas from raw microalgae.This research work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Projects CTM2011-28595-C02-01 and CTM2011-28595-C02-02), which is gratefully acknowledged. The Education, Investigation, Culture and sports Council from the Valencian Generality for the Post-Doctoral fellowship of the third co-author is also acknowledged (APOSTD/2016/104). The authors are thankful to Ion Pérez Baena from the Universitat Politècnica de Valencia, Institut de Ciència I Tecnología Animal for gently providing the ruminal fluid use in this work.Zamorano-López, N.; Borrás Falomir, L.; Giménez, JB.; Seco Torrecillas, A.; Aguado García, D. (2019). Acclimatised rumen culture for raw microalgae conversion into biogas: Linking microbial community structure and operational parameters in anaerobic membrane bioreactors (AnMBR). Bioresource Technology. 290:1-9. https://doi.org/10.1016/j.biortech.2019.121787S1929

Coupling AnMBR, Primary Settling and Anaerobic Digestion to Improve Carbon Fate when Treating Sulfate-Rich Wastewater

[EN] The present work involved an assessment of the technical feasibility of coupling AnMBR, primary settling and anaerobic digestion to treat sulfate-rich wastewater at ambient temperature. The innovative approach used focused on reducing the carbon footprint of wastewater treatment while maximizing the energy recovered from influent organic matter. In this process, primary settling reduces the COD/SO4-S ratio in the influent of the AnMBR system and completely removes organic matter by sulfate-reducing bacteria (SRB), while increasing the COD/SO4-S ratio in the sidestream anaerobic digester (AD), enhancing energy recovery and biogas quality. This approach has the significant advantage of only producing methane in the AD, so that the AnMBR produces a high-quality, methane-free effluent with no environmental impact from fugitive methane emissions. The performance of this treatment scheme was assessed by operating a demonstration-scale AnMBR plant fed by primary settled municipal wastewater at the hydraulic retention times of 25, 12 and 8.5 h. The results showed that the COD and BOD removed by SRB enabled setting the discharge limits at 25 and 12 h and lowered the carbon footprint to levels below those of an AnMBR plant fed by raw municipal wastewater, mainly by eliminating fugitive methane emissions.The authors would like to acknowledge the Ministry of Science and Innovation for supporting the project "RECREATE" (PID2020-114315RB-C22) and "BIONUTEN" (CTM2014-54980-C2-R)where this research is framed and the Ministry of Universities for the financial research fellowship of the first author (BES-2015-073403).Mateo, O.; Sanchis-Perucho, P.; Giménez, JB.; Robles, Á.; Martí, N.; Serralta Sevilla, J.; Seco, A. (2023). Coupling AnMBR, Primary Settling and Anaerobic Digestion to Improve Carbon Fate when Treating Sulfate-Rich Wastewater. Water. 15(20):1-18. https://doi.org/10.3390/w15203574118152

Measurement of the broadband complex permittivity of soils in the frequency domain with a low-cost Vector Network Analyzer and an Open-Ended coaxial probe

The performance of a handheld Vector Network Analyzer (VNA), the nanoVNA, a low-cost, open-source instrument, was evaluated. The instrument measures the complex permittivity of dielectric media from 1-port reflection parameters in the 1 – 900 MHz bandwidth. We manufactured an open-ended coaxial probe using a SMA-N coaxial adapter to perform dielectric measurements. The accuracy of the nanoVNA was comparable to that of a commercial VNA between 1 and 500 MHz according to tests in reference organic liquids, while a lack of stability was found beyond 700 MHz. The self-manufactured open-ended coaxial probe was subjected to a Finite Element Method (FEM) analysis and its electromagnetic (EM) field penetration depth was determined to be 1.5 mm at 100 MHz, being reduced to 1.3 at 900 MHz and thus demonstrating a frequency-dependent support volume. The broadband complex permittivity of three mineral soils of varied textures was obtained for a range of bulk densities and water contents from dry to water-saturated conditions. The dielectric response of the soils approximated the well-known Topp et al. (1980) equation at high frequencies. At lower frequency however, higher permittivities were exhibited due to dielectric dispersion, which emphasizes the importance of EM-based soil moisture sensor operating frequency when considering sensor calibration or comparing the response of different sensors.This research was funded by Agencia Estatal de Investigación (AEI), project numbers: AGL2016-77282-C3-3-R and PID2019-106226-C22 AEI/https:///https://doi.org/10.13039/501100011033 | Ministerio de Educación y Formación Profesional, grant numbers: FPU17/05155 and FPU19/00020. Funding for David A. Robinson was provided by a Natural Environment Research Council (NERC) award number NE/R016429/1 as part of the UK–ScaPE Programme Delivering National Capability. We also acknowledge funding from the Polish National Agency for Academic Exchange, grant number: PPI/APM/2018/1/00048/U/001. The authors wish to thank Agencia Estatal de Investigación (AEI), Ministerio de Educación y Formación Profesional, Natural Environment Research Council (NERC) and Polish National Agency for Academic Exchange (NAWA) for the funding provided. The authors also wish to thank Juan Antonio Albaladejo for his help in machining the experimental OE coaxial probe

Undergraduate experiment with fractal diffraction gratings

We present a simple diffraction experiment with fractal gratings based on the triadic Cantor set. Diffraction by fractals is proposed as a motivating strategy for students of optics in the potential applications of optical processing. Fraunhofer diffraction patterns are obtained using standard equipment present in most undergraduate physics laboratories and compared with those obtained with conventional periodic gratings. It is shown that fractal gratings produce self-similar diffraction patterns which can be evaluated analytically. Good agreement is obtained between experimental and numerical results. © 2011 IOP Publishing Ltd.We acknowledge financial support from grants DPI2008-02953 and TRA2009-0215, Ministerio de Ciencia e Innovacion, Spain. We also acknowledge support from Generalitat Valenciana through the project PROMETEO2009-077. This work has been developed by Teaching Innovation Groups from the Universitat Politecnica de Valencia (e-MACAFI) and the Universitat de Valencia (GCID35/2009).Monsoriu Serra, JA.; Furlan, WD.; Pons, A.; Gimenez Valentin, MH. (2011). Undergraduate experiment with fractal diffraction gratings. European Journal of Physics. 32:687-694. doi:10.1088/0143-0807/32/3/005S6876943

Measurement of the broadband complex permittivity of soils in the frequency domain with a low-cost vector network analyzer and an open-ended coaxial probe

The performance of a handheld Vector Network Analyzer (VNA), the nanoVNA, a low-cost, open-source instrument, was evaluated. The instrument measures the complex permittivity of dielectric media from 1-port reflection parameters in the 1 – 900 MHz bandwidth. We manufactured an open-ended coaxial probe using a SMA-N coaxial adapter to perform dielectric measurements. The accuracy of the nanoVNA was comparable to that of a commercial VNA between 1 and 500 MHz according to tests in reference organic liquids, while a lack of stability was found beyond 700 MHz. The self-manufactured open-ended coaxial probe was subjected to a Finite Element Method (FEM) analysis and its electromagnetic (EM) field penetration depth was determined to be 1.5 mm at 100 MHz, being reduced to 1.3 at 900 MHz and thus demonstrating a frequency-dependent support volume. The broadband complex permittivity of three mineral soils of varied textures was obtained for a range of bulk densities and water contents from dry to water-saturated conditions. The dielectric response of the soils approximated the well-known Topp et al. (1980) equation at high frequencies. At lower frequency however, higher permittivities were exhibited due to dielectric dispersion, which emphasizes the importance of EM-based soil moisture sensor operating frequency when considering sensor calibration or comparing the response of different sensors

Factors structuring microbial communities in highly impacted coastal marine sediments (Mar Menor lagoon, SE Spain)

Coastal marine lagoons are environments highly vulnerable to anthropogenic pressures such as agriculture nutrient loading or runoff from metalliferous mining. Sediment microorganisms, which are key components in the biogeochemical cycles, can help attenuate these impacts by accumulating nutrients and pollutants. The Mar Menor, located in the southeast of Spain, is an example of a coastal lagoon strongly altered by anthropic pressures, but the microbial community inhabiting its sediments remains unknown. Here, we describe the sediment prokaryotic communities along a wide range of environmental conditions in the lagoon, revealing that microbial communities were highly heterogeneous among stations, although a core microbiome was detected. The microbiota was dominated by Delta- and Gammaproteobacteria and members of the Bacteroidia class. Additionally, several uncultured groups such as Asgardarchaeota were detected in relatively high proportions. Sediment texture, the presence of Caulerpa or Cymodocea, depth, and geographic location were among the most important factors structuring microbial assemblages. Furthermore, microbial communities in the stations with the highest concentrations of potentially toxic elements (Fe, Pb, As, Zn, and Cd) were less stable than those in the non-contaminated stations. This finding suggests that bacteria colonizing heavily contaminated stations are specialists sensitive to change

Interactive handwriting recognition with limited user effort

The final publication is available at Springer via http://dx.doi.org/10.1007/s10032-013-0204-5[EN] Transcription of handwritten text in (old) documents is an important, time-consuming task for digital libraries. Although post-editing automatic recognition of handwritten text is feasible, it is not clearly better than simply ignoring it and transcribing the document from scratch. A more effective approach is to follow an interactive approach in which both the system is guided by the user, and the user is assisted by the system to complete the transcription task as efficiently as possible. Nevertheless, in some applications, the user effort available to transcribe documents is limited and fully supervision of the system output is not realistic. To circumvent these problems, we propose a novel interactive approach which efficiently employs user effort to transcribe a document by improving three different aspects. Firstly, the system employs a limited amount of effort to solely supervise recognised words that are likely to be incorrect. Thus, user effort is efficiently focused on the supervision of words for which the system is not confident enough. Secondly, it refines the initial transcription provided to the user by recomputing it constrained to user supervisions. In this way, incorrect words in unsupervised parts can be automatically amended without user supervision. Finally, it improves the underlying system models by retraining the system from partially supervised transcriptions. In order to prove these statements, empirical results are presented on two real databases showing that the proposed approach can notably reduce user effort in the transcription of handwritten text in (old) documents.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No 287755 (transLectures). Also supported by the Spanish Government (MICINN, MITyC, "Plan E", under Grants MIPRCV "Consolider Ingenio 2010", MITTRAL (TIN2009-14633-C03-01), erudito.com (TSI-020110-2009-439), iTrans2 (TIN2009-14511), and FPU (AP2007-02867), and the Generalitat Valenciana (Grants Prometeo/2009/014 and GV/2010/067).Serrano Martinez Santos, N.; Giménez Pastor, A.; Civera Saiz, J.; Sanchis Navarro, JA.; Juan Císcar, A. (2014). Interactive handwriting recognition with limited user effort. International Journal on Document Analysis and Recognition. 17(1):47-59. https://doi.org/10.1007/s10032-013-0204-5S4759171Agua, M., Serrano, N., Civera, J., Juan, A.: Character-based handwritten text recognition of multilingual documents. In: Proceedings of Advances in Speech and Language Technologies for Iberian Languages (IBERSPEECH 2012), Madrid (Spain), pp. 187–196 (2012)Ahn, L.V., Maurer, B., Mcmillen, C., Abraham, D., Blum, M.: reCAPTCHA: human-based character recognition via web security measures. Science 321, 1465–1468 (2008)Barrachina, S., Bender, O., Casacuberta, F., Civera, J., Cubel, E., Khadivi, S., Lagarda, A.L., Ney, H., Tomás, J., Vidal, E.: Statistical approaches to computer-assisted translation. Comput. Linguist. 35(1), 3–28 (2009)Bertolami, R., Bunke, H.: Hidden markov model-based ensemble methods for offline handwritten text line recognition. Pattern Recognit. 41, 3452–3460 (2008)Bunke, H., Bengio, S., Vinciarelli, A.: Offline recognition of unconstrained handwritten texts using HMMs and statistical language models. IEEE Trans. Pattern Anal. Mach. Intell. 26(6), 709–720 (2004)Dreuw, P., Jonas, S., Ney, H.: White-space models for offline Arabic handwriting recognition. In: Proceedings of the 19th International Conference on, Pattern Recognition, pp. 1–4 (2008)Efron, B., Tibshirani, R.J.: An introduction to bootstrap. Chapman and Hall/CRC, London (1994)Fischer, A., Wuthrich, M., Liwicki, M., Frinken, V., Bunke, H., Viehhauser, G., Stolz, M.: Automatic transcription of handwritten medieval documents. In: Proceedings of the 15th International Conference on Virtual Systems and Multimedia, pp. 137–142 (2009)Frinken, V., Bunke, H.: Evaluating retraining rules for semi-supervised learning in neural network based cursive word recognition. In: Proceedings of the 10th International Conference on Document Analysis and Recognition, Barcelona (Spain), pp. 31–35 (2009)Graves, A., Liwicki, M., Fernandez, S., Bertolami, R., Bunke, H., Schmidhuber, J.: A novel connectionist system for unconstrained handwriting recognition. IEEE Trans. Pattern Anal. Mach. Intell. 31(5), 855–868 (2009)Hakkani-Tür, D., Riccardi, G., Tur, G.: An active approach to spoken language processing. ACM Trans. Speech Lang. Process. 3, 1–31 (2006)Kristjannson, T., Culotta, A., Viola, P., McCallum, A.: Interactive information extraction with constrained conditional random fields. In: Proceedings of the 19th Natural Conference on Artificial Intelligence, San Jose, CA (USA), pp. 412–418 (2004)Laurence Likforman-Sulem, A.Z., Taconet, B.: Text line segmentation of historical documents: a survey. Int. J. Doc. Anal. Recognit. 9, 123–138 (2007)Le Bourgeois, F., Emptoz, H.: Debora: digital access to books of the renaissance. Int. J. Doc. Anal. Recognit. 9, 193–221 (2007)Levenshtein, V.I.: Binary codes capable of correcting deletions, insertions, and reversals. Sov. Phys. Dokl. 10(8), 707–710 (1966)Neal, R.M., Hinton, G.E.: Learning in graphical models. In: A View of the EM Algorithm That Justifies Incremental, Sparse, and Other Variants, Chap. MIT Press, Cambridge, MA, USA, pp. 355–368 (1999)Pérez, D., Tarazón, L., Serrano, N., Ramos-Terrades, O., Juan, A.: The GERMANA database. In: Proceedings of the 10th International Conference on Document Analysis and Recognition, Barcelona (Spain), pp. 301–305 (2009)Plötz, T., Fink, G.A.: Markov models for offline handwriting recognition: a survey. Int. J. Doc. Anal. Recognit. 12(4), 269–298 (2009)Quiniou, S., Cheriet, M., Anquetil, E.: Error handling approach using characterization and correction steps for handwritten document analysis. Int. J. Doc. Anal. Recognit. 15(2), 125–141 (2012)Rodríguez, L., García-Varea, I., Vidal, E.: Multi-modal computer assisted speech transcription. In: International Conference on Multimodal Interfaces and the Workshop on Machine Learning for Multimodal Interaction, ACM, New York, NY, USA, pp. 30:1–30:7 (2010)Serrano, N., Pérez, D., Sanchis, A., Juan, A.: Adaptation from partially supervised handwritten text transcriptions. In: Proceedings of the 11th International Conference on Multimodal Interfaces and the 6th Workshop on Machine Learning for Multimodal Interaction, Cambridge, MA (USA), pp. 289–292 (2009)Serrano, N., Castro, F., Juan, A.: The RODRIGO database. In: Proceedings of the 7th International Conference on Language Resources and Evaluation, Valleta (Malta), pp. 2709–2712 (2010)Serrano, N., Giménez, A., Sanchis, A., Juan, A.: Active learning strategies for handwritten text transcription. In: Proceedings of the 12th International Conference on Multimodal Interfaces and the 7th Workshop on Machine Learning for Multimodal, Interaction, Beijing (China) (2010)Serrano, N., Sanchis, A., Juan, A.: Balancing error and supervision effort in interactive-predictive handwriting recognition. In: Proceedings of the 15th International Conference on Intelligent User Interfaces, Hong Kong (China), pp. 373–376 (2010)Serrano, N., Tarazón, L., Pérez, D., Ramos-Terrades, O., Juan, A.: The GIDOC prototype. 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Diagnosis of prodromal and Alzheimer's disease dementia in adults with Down syndrome using neuropsychological tests

We aimed to define prodromal Alzheimer's disease (AD) and AD dementia using normative neuropsychological data in a large population-based cohort of adults with Down syndrome (DS). Cross-sectional study. DS participants were classified into asymptomatic, prodromal AD and AD dementia, based on neurologist's judgment blinded to neuropsychological data (Cambridge Cognitive Examination for Older Adults with Down's syndrome [CAMCOG-DS] and modified Cued Recall Test [mCRT]). We compared the cutoffs derived from the normative data in young adults with DS to those from receiver-operating characteristic curve (ROC) analysis. Diagnostic performance of the CAMCOG-DS and modified Cued Recall Test (mCRT) in subjects with mild and moderate levels of intellectual disability (ID) was high, both for diagnosing prodromal AD and AD dementia (area under the curve [AUC] 0.73-0.83 and 0.90-1, respectively). The cutoffs derived from the normative data were similar to those derived from the ROC analyses. Diagnosing prodromal AD and AD dementia in DS with mild and moderate ID using population norms for neuropsychological tests is possible with high diagnostic accuracy

Differential antigenicity of individual Mycoplasma hyorhinis variable lipoproteins

The Mycoplasma hyorhinis (Mhr) variable lipoprotein (Vlp) family, comprising Vlps A, B, C, D, E, F, and G, are highly variable in expression, size, and cytoadhesion capabilities across Mhr strains. The ‘Vlp system’ plays a crucial role in cytoadhesion, immune evasion, and in eliciting a host immunologic response. This pilot study described the development of Vlp peptide-based ELISAs to evaluate the antigenic reactivity of individual Vlps against Mhr antisera collected throughout a longitudinal study focused on Mhr strain 38983, reproducing Mhr-associated disease under experimental conditions. Specifically, serum samples were collected at day post-inoculation 0, 7, 10, 14, 17, 21, 24, 28, 35, 42, 49, and 56 from Mhr- and mock (Friis medium)-inoculated cesarean-derived, colostrum-deprived pigs. Significant Mhr-specific IgG responses were detected at specific time points throughout the infection, with some variations for each Vlp. Overall, individual Vlp ELISAs showed consistently high accuracy rates, except for VlpD, which would likely be associated with its expression levels or the anti-Vlp humoral immune response specific to the Mhr strain used in this study. This study provides the basis and tools for a more refined understanding of these Vlp- and Mhr strain-specific variations, which is foundational in understanding the host immune response to Mhr.This article is published as Magtoto, P.D., Arruda, B.L., Magtoto, R.L., Mora-Díaz, J.C., Opulencia, R.B., Baum, D.H., Zimmerman, J.J. and Giménez-Lirola, L.G., 2024. Differential antigenicity of individual Mycoplasma hyorhinis variable lipoproteins. Veterinary Immunology and Immunopathology, p.110768. doi: https://doi.org/10.1016/j.vetimm.2024.110768. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted